"What's wrong with a website" is that it is not part of a relevance-curated, pushed feed that people are already using.

If you look at pre-idiot-king Twitter, when there's an earthquake it fills up with comments about it, and very rapidly. Geological advisories get retweeted, again very rapidly. It turns out that yeah, this kinda actually works!

I am not, I stress, saying that I like that this is the reality of things, but it speaks for itself.